1. Field of the Invention
The present invention relates to novel esters of certain cyclopropane derivatives which exhibit pesticidal properties, especially insecticidal and acaricidal properties. The invention also relates to pesticidal compositions comprising the novel esters and to a method of combating insect or acarid pests.
2. Description of the Prior Art
It is well known that certain substituted cyclopropane carboxylic acid derivatives are an important class of insecticides called "synthetic pyrethroids". These synthetic pyrethroids have been of considerable interest because of their quick knock-down activity, low persistence as toxic residues and their low mammalian toxicity. Literally hundreds of articles and patents have been published with teachings directed to this class of insecticidal compounds.
In our prior U.S. patent application, Ser. No. 510,197, filed Sept. 30, 1974, now U.S. Pat. No. 3,950,535, we disclose certain novel cyclopropane derivatives that conform to the formula ##STR1## in which R.sup.1 and R.sup.2 are alkyl, R.sup.3 is hydrogen, alkynyl or cyano, R.sup.4 is preferably a substituted phenyl group, such as 3-phenoxyphenyl and n is an integer of from 2-5.
Many prior art insecticidal esters have been prepared featuring differences in either the alcohol or acid portion of the ester molecule. U.S. Pat. No. 3,823,177, July 9, 1974 relates to certain spiro-carboxylic acids and their allethrolone esters. U.S. Pat. No. 3,786,052, Jan. 15, 1974 relates to numerous cyclopropane carboxylic acids and esters including allethrolone esters of 2-(isobut-1'-enyl)spiro[2,5]octane-1-carboxylic acid, 2-(isobut-1'-enyl)spiro[2,4]heptane-1-carboxylic acid and 2,2,5-trimethylspiro[2,5]oct-4-ene-1-carboxylic acid. Netherlands publication No. 7307,130, Nov. 27, 1973 relates to esters of dihalovinyldimethylcyclopropane carboxylic acids which esters may be .alpha.-substituted on the alcohol moiety by a cyano or ethynyl group. U.S. Pat. No. 3,835,176, Sept. 10, 1974 relates to .alpha.-cyanobenzyl cyclopropane carboxylates such as .alpha.-cyano-3-phenoxybenzyl 2',2'-dimethyl-3'-vinylcyclopropane carboxylate. U.S. Pat. No. 3,758,504, Sept. 11, 1973 relates to various vinylcyclopropane carboxylates including 3-phenoxybenzyl 2',2'-dimethyl-3'-vinylcyclopropane carboxylate.